Elsevier

Seizure

Volume 15, Issue 1, January 2006, Pages 41-48
Seizure

Adenosine A1 and A2A receptors of hippocampal CA1 region have opposite effects on piriform cortex kindled seizures in rats

https://doi.org/10.1016/j.seizure.2005.10.006Get rights and content
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Summary

In this study the role of adenosine A1 and A2A receptors of the hippocampal CA1 region on piriform cortex-kindled seizures was investigated in rats. Animals were kindled by daily electrical stimulation of piriform cortex. In fully kindled rats, N6-cyclohexyladenosine (CHA; a selective A1 receptor agonist), 1,3-dimethyl-8-cyclopenthylxanthine (CPT; a selective A1 receptor antagonist), CGS21680 hydrochloride (CGS, a selective A2A receptor agonist) and, ZM241385 (ZM, a selective A2A receptor antagonist) were microinfused bilaterally into the hippocampal CA1 region. Rats were stimulated and seizure parameters were measured. Obtained results showed that microinjection of CHA (10 and 100 μM) decreased the afterdischarge duration (ADD), stage 5 seizure duration (S5D) and seizure duration (SD), and significantly increased the latency to stage 4 (S4L). Intra-hippocampal CPT increased ADD at the dose of 20 μM. Pretreatment of rats with CPT (10 μM) before CHA (10 μM), significantly reduced the effect of CHA on seizure parameters. On the other hand, microinjection of CGS (200 and 500 μM) increased ADD, but of ZM had no effect on seizure parameters. Pretreatment of rats with ZM (50 μM) before CGS (500 μM), significantly reduced the effect of CGS on seizure parameters. The results suggest that the facilitatory role of the hippocampal CA1 region in relaying or spreading of piriform cortex kindled seizures is decreased by the activation of adenosine A1 receptors and increased by A2A receptors.

Keywords

Seizure
Adenosine
Piriform cortex
Hippocampus

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